Experimental Study on Cyclic Shear of High Strength Bolted Slip-Critical Connection of Sandblasted Steel Plate

To solve the problem of shear resistance for bolted connection under earthquakes, cyclic loading tests were performed for 36 high-strength bolted shear connection specimens with sandblasted steel, which were double shear, single shear and double shear with copper sheets connection with different bolt sizes and hole patterns. The shear resistance, mean-slip coefficient before slip, pre-slip deformation, stiffness, the shear resistance after slipping, measured friction coefficient, nominal friction coefficient and bolt tension after the slip were obtained. Results show that the stiffness of double shear connection is larger than that of single shear connection whose pre-slip deformation is 1.8 times that of the former. The copper sheets between sandblasted steel plates reduce the slipping noise, friction discreteness and increase the mean-slip coefficient of specimens about 16.1%. The friction between the washer and the steel plates improves the shear resistance of single shear connections. The modified formula of mean-slip resistance was proposed for single shear connection. The recommended value of pre-slip deformation was given for double shear, single shear and double shear with copper sheets connection. The formulas of slip resistance were proposed for three types of connection.